Web forming apparatus employing intermediate web forming and spreading section

Abstract

An apparatus for increasing the width, or cross-machine-direction dimension of a fluid-entrained (e.g., air-entrained) stream of fibers to form a fibrous web that is wider than the stream of fibers. A rotatable spreading roll having a foraminous outer surface obliquely intercepts the open downstream end of a conveying duct through which the fluid-entrained stream of fibers is directed, and an intermediate web, wider than the stream of fiber in the first conveying duct, is deposited on this foraminous surface. The spreading roll is rotated to direct the intermediate web into communication with the upstream end of a second conveying duct, and a pressure differential established through the apparatus functions to relaunch the fibers of the intermediate web into the second conveying duct, and ultimately onto a foraminous forming surface to form a fibrous web product that is wider than the initially formed stream of fibers in the first conveying duct.

Having described my invention I claim: 
     
       1. A web forming apparatus including: a first conveying duct through which a fluid-entrained stream of fibers is adapted to move from an upstream end to a downstream end thereof;   an intermediate rotatable spreading roll obliquely oriented to the first conveying duct and intercepting the downstream end thereof between laterally spaced-apart duct sidewalls, said roll including a foraminous member having an outer surface for receiving the fluid-entrained fibers thereon and passing the fluid therethrough, said foraminous outer surface having a lateral dimension between the duct sidewalls that is greater than the width of the duct at its open downstream end, as measured between the duct sidewalls in a direction generally normal to the direction of fiber flow;   a second conveying duct having an upstream end spaced from the downstream end of the first conveying duct and being intercepted by the outer surface of the spreading roll; and   means for establishing a pressure differential across the apparatus to aid in initially depositing the fibers on the outer periphery of the intermediate spreading roll and relaunching the fibers into the second conveying duct adjacent the upstream end thereof.   
     
     
       2. The apparatus of claim 1 wherein said intermediate spreading roll includes a plurality of internal, axially spaced-apart disks providing internal fluid-flow channels communicating, through the foraminous member of the roll, with the interior of the first and second conveying ducts. 
     
     
       3. The apparatus of claims 1 or 2 including a foraminous forming surface intercepting the downstream end of the second conveying duct for receiving the relaunched fibers in the form of a fibrous web. 
     
     
       4. The apparatus of claim 3 including a fiberizing means adjacent the upstream end of the first conveying duct for separating fibers from a fibrous feed and directing the fibers into the upstream end of said first conveying duct.